For 21 years the TOP500 list of supercomputers serves as a “Who’s Who” in the field of High Performance Computing (HPC). The TOP500 list was started in 1993 as a project to compile a list of the most powerful supercomputers in the world. It has evolved from a simple ranking system to a major source of information to analyze trends in HPC. As such it is widely used and cited by numerous speakers and media whenever references to the development of supercomputing abilities are needed. The TOP500 has traditionally been published at the ISC in June and at the SC in November of each year since 1993. The 43rd TOP500 list will be published in June 2014 at the ISC14.